Hermetically sealed containers with unitary closures are known. Such containers typically have a body portion, a neck portion, and a top or closure structure to close and seal the opening in the neck portion.
It is also known to provide such containers with means for permitting the containers to be opened by breaking off the sealed closure at the top of the container or on the neck portion of the container between the container sealed top and the container body portion.
To facilitate the opening of such a container, a frangible web is typically provided between the container neck portion and the closure structure. The frangible web comprises a reduced thickness region in the wall of the material forming the container. Such a container is opened by twisting or bending a part of the container on one side of the frangible web so as to rupture or sever the reduced thickness region of material at the frangible web.
Containers incorporating the above-described frangible web structure are usually formed from a thermoplastic material such as a polyolefin. Such containers are conventionally fabricated by blow molding and/or vacuum forming in split mold parts that close along a parting plane. The formed container typically has a ridge or seam of material on the exterior surface along the parting plane.
The frangible web can be formed in the container neck by conventional techniques during the container molding processes. Of course, before the top closure is molded on the container, the container is filled with the desired contents from a filling nozzle. A typical "formed, filled, and sealed" container of this type is disclosed in U.S. Pat. No. 4,671,763. This patent also discloses the fabrication process as well as the apparatus therefor.
The above-described hermetically sealed, thermoplastic containers are used to package a variety of materials. Such containers have been found to be especially suitable for use in dispensing sterile fluids, such as pharmaceutical solutions and ointments. While these conventional containers function satisfactorily for the purposes for which they have been designed, it would be desirable if the advantages offered by such hermetically sealed containers could be employed in other applications. Specifically, it would be beneficial to be able to use such a container for dispensing a material into a body cavity.
However, the use of such containers for these purposes is not altogether satisfactory. Many such containers are blow molded or vacuum formed from polypropylene in order to provide the characteristics desired for structural integrity, compatibility with the container contents, ease of molding, etc. The ridge or seam formed during container manufacture at the parting plane of such molded containers is relatively prominent and either cannot be altogether eliminated by the usual molding or post-molding flash removal techniques, or require uneconomical procedures to do so. The ridge or seam that is present can irritate if not damage, sensitive tissues and membranes, however. This is a particular problem with respect to applications wherein the user wishes to insert the dispensing end of the container into a body cavity for dispensing the container contents directly into the cavity. For example, this problem militates against the use of a hermetically sealed, blow-molded (or vacuum formed), polypropylene dispensing container for dispensing vaginal lubricants and the like directly into the vagina.
Further, when the closure is removed from the container by tearing or twisting the closure along the connecting frangible web, the exposed dispensing orifice on the container may be surrounded by a relatively rough, uneven, or jagged region which defines the surface at the broken frangible web. This could also irritate or scratch sensitive tissues and membranes.
Although attempts have been made to provide molding processes which reduce both the parting line ridge and the roughness of the broken portion of the frangible web after removal of the closure, such attempts to date have not been completely satisfactory with respect to some intended applications. In view of this, it would be desirable to provide an improved hermetically sealed dispensing package with the convenience of a twist-off closure but without rough edges or portions contacting the body tissues during use.
It would also be advantageous if such an improved package could be relatively small and selfcontained.
Further, it would be beneficial if such an improved package could be readily manufactured by conventional, and relatively inexpensive, processes.
The present invention provides the aforementioned benefits and features.